Standard housing design

Designs and variants

have two oblong holes cast into the base for attachment bolts to enable exact positioning of the housing during mounting to fully exploit the potential of CARB toroidal roller bearings to accommodate thermal elongation of the shaft

have four holes cast in the base for attachment bolts where the holes are:

open-ended for spherical roller bearing

oblong for CARB toroidal roller bearings, to enable exact positioning of the housing during mounting to fully exploit the potential of CARB toroidal roller bearings to accommodate thermal elongation of the shaft.

consist of a cap, base and two covers with integrated seals, where the inboard cover is split to enable removal of the cover without removing the cap

have two integral flanges in the cap, with a hole cast into each one

have four holes in the base for attachment bolts where the holes are

drilled for spherical roller bearings

oblong for CARB toroidal roller bearings, to enable exact positioning of the housing during mounting to fully exploit the potential of CARB toroidal roller bearings to accommodate thermal elongation of the shaft.

SDM Yankee cylinder housings on rockers (fig. 4) can still be supplied by SKF. For additional information, contact the SKF application engineering service.

SBF and SBP housings (predecessors to SBFN housings and SBPN housings respectively, which can still be supplied by SKF

Features and Benefits

Optimized designs
The housing designs are developed together with leading OEMs and are optimized to accommodate the arduous operating conditions present in paper machines.

Effective and maintenance-free (CHECK!?!)seals
SBFN and SBPN housings have upgraded labyrinth seals compared to their predecessors, providing extra protection against liquid contaminants during operation and high pressure wash-downs. The seals also virtually eliminate oil leaks, even for high oil flow rates. SDM housings have a maintenance-free, non-contact gap-type seal incorporated into each cover.

for connections with inch threads
SBFN, SBPN and SDM housings can be supplied with inch threads for connectors. Threads are in accordance with modified American National Form NS threads and all screws and bolts have UNC threads. Oil inlets and outlets are tapped with NPTF threads and holes for condition monitoring sensors have 5/16-18 UNC threads. This housing variant is identified by the designation suffix N9, e.g. SBPN 3140 RAN9.

for steam joint connections
SBPN and SDM housings can be supplied with a modified cover to accommodate steam joint connections on through shafts (fig. 5) Various cover designs are available to suit the type of steam joint. This housing variant is identified by the designation suffix B, followed by a number (from 1 to 99) indicating the cover design, e.g. SDM 30/670 B2RA.

for the wet section
SBFN housings for the wet section are available on request.

for rope sheaves
SBPN drying cylinder housings can be supplied with one side machined to fit the rope sheave.

for four-bolt mounting
SBFN housings can be supplied with four holes cast into the base for attachment bolts.

Table 1 provides an overview of the characteristics and suitability of the sealing solutions for SKF housings for paper machines. This information should be used as a guideline, which cannot substitute for testing a seal in its application.

SBFN (fig. 6) housings have a labyrinth ring, bolted to the shaft to form an axial labyrinth seal integrated in each cover. Shafts require machined grooves that act as oil flingers.

SBPN (fig. 7) housings have a labyrinth ring, bolted to the shaft to form an axial labyrinth seal integrated in each cover.

End covers are available for housings mounted at the end of a shaft.

SDM housings are equipped with gap-type seals and split oil flinger rings (fig. 8), integrated in the covers. The flinger ring, which is split and mounted directly onto the shaft, is positioned axially by tightening the ring screw into a tapped hole on the shaft.

is not affected by most lubricating or engine oils, cutting fluids or alkalescent washing chemicals

Housings can be repainted with most water or solvent based 1- or 2-component paints and can be supplied painted according to customer specification. These housings are identified by the designation suffix P, followed by a number, e.g. SBFN 3136 RA/P45. Unpainted surfaces are protected by a solventless rust inhibitor.